: Northstar main cap bolts

05-19-04, 11:04 PM
Are the Northstar main cap bolts prone to pulling threads out like the head gaskets? I have a '98 Deville 140K just time serted the heads, went to replace the oil pan gasket, manifold.... and realized the main cap bolts went through the plate. I have to replace the plate due to oil leakage. Will I have to be concerned about time-serting the mains? any tricks tips pointers? pan is off and 46 is on a hoist. need help..... Thanks in advance

05-20-04, 02:18 AM
I just did a complete re-seal on mine. Most of the head bolts were stripped but the main bolts were all good and re-installed without incident. I beleive this is usual ly the case, so go ahead and pull them. One tip, when you break them loose they will "snap" loose a sudden force. So use a breaker bar on them and not a ratchet. The ratchet has an aftershock that can snap the bolt in two, even though it loosened. This is less likely to happen with a breaker bar.

05-20-04, 09:52 AM
I haven't heard of a Northstar pulling any of the Main stud threads either. Mine were fine as well. One tip that was pointed out to me by Bbob was the install of the rear main seal. When you break the case half, which is what I would recommend if you've gotten this far. When you go to re-install the the case half and before you torque the mains slip the rear main into it's position and then tighten the and torque the mains as per the manual.

Makes life alot easier.... good luck with the fixes. Been there done all that and I have a bunch of dirty tee shirts to prove it. :rolleyes2

05-20-04, 10:10 AM
You shouldn't have any trouble at all with the main bolts.

If you split the cases you can re-use the main bearing inserts but do NOT be tempted to take a rod cap off to look at the bearing....unless you replace the bearings. Rod bearing shells are a one shot deal...if you take it apart, replace it or it will fail if you reuse it.

05-20-04, 01:13 PM
Reuse or replace main fasteners?? Bbob?

05-20-04, 01:41 PM
The bolts for the lower end can be reused....

Actually, the bolts for the lower end of the engine are used twice anyway!! The engine is bolted together , along with a steel spacer plate substituting for the oil manifold plate, with the production fasteners for final machining of the main bearing bores and other details on the block. At the end of the block machining process the LCC is de-bolted and separated for final assembly. This leaves a LOT of main bearing bolts lying around....so....they are sorted, inspected, washed, stripped of the antifriction coating, recoated, and returned to the engine plant where they are used on the final assembly line for assembly of new engines. So, there is a good chance that the main bolts have already been "used" twice when the engine is built. The main bolts are not put into yield so they can be used a number of times.

I thought you were supposed to be in Monaco.....????

05-21-04, 06:49 AM
I am!! 8) 8) :bouncy: Jim

05-21-04, 06:56 AM
So is it Mon-AH-co ...... I understand the locals are about 50/50 on this and MON-ah-co.